Along with the development of information communication, a new-type high-performance flexible element is recently needed. In order to operate such an electronic element, a flexible energy element technique for supplying and storing an energy source is required together with a high-performance semiconductor element. However, until now, it has been impossible to implement a high-performance energy producing or storing technique due to a limit of a flexible substance which does not endure a high-temperature process. A general power producing element such as a piezoelectric element is manufactured from a hard silicon substrate and then intactly used because such an element is manufactured through a high-temperature semiconductor process. However, due to such a limit of an element substrate, applications of piezoelectric elements, secondary batteries or the like are limited.
In particular, a piezoelectric element is one of elements whose effect is limited due to such a limitation. The piezoelectric element means an element which exhibits a piezoelectricity phenomenon. The piezoelectric element is also called a piezoelectric effect element, and crystal, tourmaline, Rochelle salt or the like have been used as piezoelectric elements from old times. Artificial crystals such as lead zirconium oxide, barium titanate (BaTiO3, hereinafter, also referred to as BTO), ammonium dihydrogen phosphate, tartaric acid ethylene diamine or the like, recently developed, also have excellent piezoelectricity, and more excellent piezoelectricity may be induced by doping.
At the present, the piezoelectric element is used for generating electricity according to a pressure applied from the outside. However, if the piezoelectric element is applied to a flexible substrate which may freely bend, the piezoelectric element may instantly convert the bending of the flexible substrate into electric energy. From now, however, a piezoelectric element, particularly a large-scale piezoelectric element, applied to a flexible substrate is not yet proposed. Further, in order to charge the generated electric energy, a charging unit is generally provided separately out of a BTO element. However, this occupies an excessive area of a device which uses the piezoelectric element.
In addition, a nanogenerator manufactured through a high-temperature process should be separated from a sacrificial substrate, which is a very important process, but at the present, a general element is separated by means of an etching process using a chemical solution. However, in this case, the device may be damaged by the etching solution, workers may be exposed to dangerous working environments, and the device may be deformed by the etching solution.